Administrivia CSCE150A CSCE150A Computer Science & Engineering - PDF document

Administrivia CSCE150A CSCE150A Computer Science & Engineering 150A Administrivia Problem Solving Using Computers Administrivia Roll Overview Overview Syllabus Hardware Hardware Lecture 01 - Course Introduction Course Webpage: Software Software Example Example http://cse.unl.edu/~sscott/teach/Classes/cse150AF09/ Program Program Prerequisite test/placement test: Pseudocode Stephen Scott Pseudocode http://ncite.unl.edu/cs_placement/ Flowchart Flowchart (Adapted from Christopher M. Bourke) Control Control CSE: UNIX, logging in, usage agreement, CodeLab → Lab Structures Structures Hello World Hello World Program Program Fall 2009 1 / 43 2 / 43 Intro CSCE Courses Overview of Computers and Programming CSCE150A CSCE150A CSCE 101: Fundamentals of Computing (Alice) gives a breadth-oriented overview of the field of computer science. CSCE 150A: Introduction to Problem Solving with Computers Administrivia Administrivia (C) teaches fundamentals of problem solving via programming. Overview Overview Computer Hardware Hardware CSCE 150E: Introduction to Computer Programming for Hardware Computer Software Software Scientists and Engineers (Fortran or Matlab) teaches fundamentals Software Software Development (Problem Solving) Example Example of problem solving via programming. Program Program CSCE 150M: Multimedia Approach to Computing (Python) Pseudocode Pseudocode Pseudocode teaches fundamentals of problem solving via programming. Flowchart Flowchart Flowchart Control CSCE 155: Computer Science I (Java) is the first course towards Control Structures Structures the major or minor in CS. For those who pass 150 or score well on Hello World Hello World the Placement Exam: http://ncite.unl.edu/cs_placement/ Program Program CSCE 156: Computer Science II (C++) is the second course towards the major or minor in CS. 3 / 43 4 / 43 Introduction to Computers Different Types of Computers I CSCE150A CSCE150A Embedded Systems: iPod, cell phones, etc. Administrivia Computers receive, store, process, and output information. Administrivia Overview Overview Personal Computers: used by everyday people and typically used by Computers can deal with numbers, text, images, graphics, and Hardware Hardware just one person at a time sound, to name a few. Software Software Mainframes: used for real-time systems, ATMs, and such; very Computers are useless without programming. Example Example Program Program powerful and reliable computers Programming languages allow us to write programs and thus Pseudocode Pseudocode Supercomputers: used by research laboratories for computationally communicate with computers. Flowchart Flowchart intensive applications such as weather forecasting; the largest It takes our code and converts it into a format so the computer can Control Control capacity and fastest mainframes Structures Structures understand it. Often configured as a cluster of several smaller computers Hello World Hello World Program Program 5 / 43 6 / 43

Different Types of Computers II Hardware vs. Software CSCE150A CSCE150A Administrivia Administrivia Overview Overview Hardware is the equipment used to perform the necessary Hardware Hardware computations. E.g. CPU, monitor, keyboard, mouse, printer, etc. Software Software Software is the programs that enable us to solve problems with a Example Example computers by providing it with a list of instructions to follow. Program Program Examples: Word, Firefox, games, etc. Pseudocode Pseudocode Figure: PrairieFire is a 98-node Beowulf cluster, originally constructed in 2002. Flowchart Flowchart Firmware - small programs stored in non-volatile memory It originally scored an HPL benchmark number of 442.50 GFlops, which was then Control Control Structures Structures the 107th most powerful supercomputer in the world, according to the TOP500 Hello World Hello World supercomputer list. See http://rcf.unl.edu/prairiefire/index.php Program Program 7 / 43 8 / 43 Computer Hardware Memory I CSCE150A CSCE150A Main Memory Memory is an essential component in any computer. Administrivia Administrivia RAM - Random Access Memory - Memory that can be accessed in Overview Overview any order Memory Cell - the storage location Hardware Hardware ROM - Read Only Memory - Memory that cannot be written to Software Software Address - the location of the memory cell relative to other memory Secondary Memory - Hard disks, flash drives, CDs, DVDs, etc. Example Example cells Program Program Central Processing Unit (CPU) - Coordinating all computer Content - what is stored in the memory cell Pseudocode Pseudocode operations and perform arithmetic and logical operations Flowchart Flowchart All programs run in memory Input/Output Devices - Monitor, printer, keyboard, & mouse Control Control Every memory cell has content, whether we know it or not. So always Structures Structures Computer Networks (not hardware, but configuration of the initialize variables Hello World Hello World hardware) - WAN, LAN, MAN, Wireless LAN Program Program 9 / 43 10 / 43 Memory II Memory III CSCE150A CSCE150A bit - deriving from b inary dig it , is either a 0 or 1 Address Contents byte - a memory cell is actually a grouping of smaller units called 0 -27.2 bytes. A byte is made up of 8 bits Administrivia Administrivia 1 42 Overview Overview Example: A single character, H requires a byte to store 2 0.005 Hardware Hardware 3 -26 kilobyte: 1024 bytes ( not 1000 bytes) Software Software 4 H In general, memory sizes are powers of two, 2 10 = 1024 is the power Example Example . . Program Program . . of two closest to 1 , 000 . . Pseudocode Pseudocode megabyte: 2 20 = 1 , 048 , 576 bytes (or 1024 kilobytes) 998 x Flowchart Flowchart 999 75.62 gigabyte: 2 30 = 1 , 073 , 741 , 824 bytes (or 1024 megabytes) Control Control Structures Structures Figure: Portion of Memory Cells kilo-, mega-, giga- may refer to bytes in base-10 in some contexts Hello World Hello World Program Program (network data) or when discussing bits 11 / 43 12 / 43

Memory Memory Exercise Exercise CSCE150A CSCE150A Problem Problem Administrivia Administrivia A certain portable MP3 player is advertised as a having a “30GB” hard A certain portable MP3 player is advertised as a having a “30GB” hard Overview Overview drive. In reality, it has 30 , 000 , 000 , 000 bytes. How many actual (base-2) drive. In reality, it has 30 , 000 , 000 , 000 bytes. How many actual (base-2) Hardware Hardware gigabytes does it have? gigabytes does it have? Software Software Example Example Program Program Divide by the number of bytes in a gigabyte: Pseudocode Pseudocode Flowchart Flowchart Control Control Structures Structures Hello World Hello World Program Program 13 / 43 13 / 43 Memory Memory Exercise Exercise CSCE150A CSCE150A Problem Problem Administrivia Administrivia A certain portable MP3 player is advertised as a having a “30GB” hard A certain portable MP3 player is advertised as a having a “30GB” hard Overview Overview drive. In reality, it has 30 , 000 , 000 , 000 bytes. How many actual (base-2) drive. In reality, it has 30 , 000 , 000 , 000 bytes. How many actual (base-2) Hardware Hardware gigabytes does it have? gigabytes does it have? Software Software Example Example Program Program Divide by the number of bytes in a gigabyte: Divide by the number of bytes in a gigabyte: Pseudocode Pseudocode Flowchart Flowchart 30 , 000 , 000 , 000 bytes 30 , 000 , 000 , 000 bytes 1024 × 1024 × 1024 bytes-per-gigabyte = 27 . 93 GB Control Control 1024 × 1024 × 1024 bytes-per-gigabyte Structures Structures Hello World Hello World Program Program 13 / 43 13 / 43 Computer Software I Computer Software II CSCE150A CSCE150A Administrivia Administrivia Operating System - controls the interaction between machine and user Overview Overview Hardware Hardware Communicate with user Software Software Example Manage memory Example Program Program Collect input/Display output Pseudocode Pseudocode Flowchart Flowchart Read/write data Control Control Structures Structures Hello World Hello World Program Program Figure: OS/device interaction 14 / 43 15 / 43